This invention relates to gas discharge devices and more particularly, but not exclusively, to thyratrons.
A thyratron is a device which includes an anode and a cathode. The cathode may be what is termed a `cold cathode`, that is, one which emits electrons when it is subjected to a large enough electric field. Such cold cathodes have advantages over heated cathodes in that they become emitting as soon as a discharge voltage is established between the anode and the cathode. Also a cold cathode does not require a heater filament.
However, conventional cold cathodes suffer from a significant disadvantage when used in thyratrons or lasers in that the lifetime of a cold cathode is generally short, being of the order of 50 to 100 hours.